On newer chrome devices it's possible if you have connected before.
However if you're asking about the Bluetooth prompt specifically then right now I don't have a way to disable it, however you could use the Puck.js library which has the same API and is bluetooth only, so doesn't have the prompt: http://www.espruino.com/Web+Bluetooth
It'll still ask you which device to connect to though!
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I just added another possible answer to that stackoverflow question linked above: https://stackoverflow.com/questions/54132319/override-default-behavior-of-navigator-bluetooth-requestdevice/63454399#63454399
On newer chrome devices it's possible if you have connected before.
However if you're asking about the Bluetooth prompt specifically then right now I don't have a way to disable it, however you could use the
Puck.js
library which has the same API and is bluetooth only, so doesn't have the prompt: http://www.espruino.com/Web+BluetoothIt'll still ask you which device to connect to though!